common,test: g_ceph_context->put() upon return

prior to this change, global_init() could create a new CephContext
and assign it to g_ceph_context. it's our responsibilty to release
the CephContext explicitly using cct->put() before the application
quits. but sometimes, we fail to do so.

in this change, global_init() will return an intrusive_ptr<CephContext>,
which calls `g_ceph_context->put()` in its dtor. this ensures that
the CephContext is always destroyed before main() returns. so the
log is flushed before _log_exp_length is destroyed.

there are two cases where global_pre_init() is called directly.
- ceph_conf.cc: g_ceph_context->put() will be called by an intrusive_ptr<>
  deleter.
- rgw_main.cc: global_init() is called later on on the success code
  path, so it will be taken care of.

Fixes: http://tracker.ceph.com/issues/17762
Signed-off-by: Kefu Chai <kchai@redhat.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/src/ceph_mgr.cc b/src/ceph_mgr.cc
index 9365fb83fd1..acdddec194e 100644
--- a/src/ceph_mgr.cc
+++ b/src/ceph_mgr.cc
@@ -35,8 +35,9 @@ int main(int argc, const char **argv)
   argv_to_vec(argc, argv, args);
   env_to_vec(args);
 
-  global_init(NULL, args, CEPH_ENTITY_TYPE_MGR, CODE_ENVIRONMENT_DAEMON, 0,
-              "mgr_data");
+  auto cct = global_init(NULL, args, CEPH_ENTITY_TYPE_MGR,
+			 CODE_ENVIRONMENT_DAEMON, 0,
+			 "mgr_data");
   // For consumption by KeyRing::from_ceph_context in MonClient
   g_conf->set_val("keyring", "$mgr_data/keyring", false);